xerte 3.8 upgrade ldap issue

Hi,
Last week, I upgraded Xerte from 3.7 to 3.8 in our development environment.
Since the upgrade, it is not accepting any (LDAP) logins from the home page.
The logs I've checked aren't helpful, and the settings on the management screen and in the database that I've checked appear to be the same as our production environment, and that environment works OK.
Settings on the management are saving correctly. The browser cache has been cleared multiple times, and the Apache reboot multiple times too.
Has anyone else had a similar issue, and/or is there something obvious that I've missed or should re-try?
Thank you.

Could you please verify that you are using 3.8.3.

You can do that by browsing to https(s)/<xerte url>/version.txt

To get a better understanding of what is happening, you can set the $development variable to true in config.php (around line 43) and inspecting the file error_logs/debug.log after a login attempt.